/*
 * Copyright (c) 2011, Nikolaus Moll
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the gradecalculator.net nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
package net.gradecalculator.grade.de.impl;

import net.gradecalculator.plugin.grade.exceptions.IllegalGradeException;
import net.gradecalculator.plugin.grade.interfaces.IGradeCommon;

public abstract class AbstractGrade implements IGradeCommon {
	private float grade = 0;
	private float gradeSum = 0;
	private float weight = 0;

	public AbstractGrade()
	{
	}
	
	public AbstractGrade(final String grade, final float weight)
	{
		setGrade(grade, weight);
	}
	
	@Override
	public void setGrade(final String grade, final float weight) {
		this.grade = GradeUtil.stringToFloat(grade);
		this.weight = weight;
		this.gradeSum = this.grade * this.weight;
		
		validate();
	}

	@Override
	public float getWeight()
	{
		return weight;
	}
	
	public float getGradeAsFloat() {
		return grade;
	}
	
	protected void validate()
	{
		if (this.weight == 0) {
			return;
		}
		
		if (!GradeValidator.getInstance().isValid(this.grade)) {
			throw new IllegalGradeException("Illegal grade " + floatToString(this.grade, 2));
		}
	}

	protected void add(final AbstractGrade grade)
	{
		this.gradeSum += grade.gradeSum;
		this.weight += grade.weight;
		this.grade = this.gradeSum / this.weight;

		validate();
	}
	
	protected void add(final AbstractGrade grade, final float weight)
	{
		this.gradeSum += grade.grade * weight;
		this.weight += weight;
		this.grade = this.gradeSum / this.weight;

		validate();
	}
		
	protected String floatToString(final float f, final int decimals)
	{
		return String.format("%." + (decimals + 1) + "g%n", f).replace('.', ',').trim();		
	}
	
	@Override
	public String toString()
	{
		return getGrade();
	}
}
